GREENSBORO, N.C. (AP) - Chelsea Gray and fifth-ranked Duke kept throwing the ball away, fumbling it out of bounds or losing it in traffic.

All those turnovers helped spark North Carolina State's 75-73 upset of the Blue Devils in the quarterfinals of the Atlantic Coast Conference tournament Friday. The Blue Devils turned the ball over 22 turnovers and the Wolfpack converted them into 26 points.

''I think we were just forcing things that weren't necessarily there at times and trying to make the harder pass,'' said Gray, who had a career-high eight turnovers. ''I know personally, trying to make the harder pass rather than the easier pass to the wings or something like that. But I think it was just forcing the issue instead of just taking what came to us.''

Duke held N.C. State to 39 percent shooting, but the turnovers helped the Wolfpack stay close even as the Blue Devils threatened to take control.

Duke's biggest lead was six midway through the second half, though the Blue Devils promptly committed turnovers on the next two possessions to stop their momentum.

Almost half of N.C. State's 39 points in the second half (17) came off giveaways.

Bonae Holston and Marissa Kastanek each scored 16 points to lead N.C. State.

Myisha Goodwin-Coleman added 12 points for the ninth-seeded Wolfpack (18-14), who ended a six-game losing streak to the Blue Devils. N.C. State also scored 21 second-chance points to help pull off the upset.

Gray scored a career-high 25 points to lead the top-seeded Blue Devils (24-5), who cut an eight-point deficit to two in the final seconds. But Gray missed the front end of a 1-and-1 with 2.9 seconds left, and the ball went out of bounds to N.C. State.

The Wolfpack inbounded the ball to Goodwin-Coleman to dribble out the final 1.8 seconds, sending N.C. State bench spilling onto the court to celebrate another tournament win under third-year coach Kellie Harper.

Harper, the successor to late Hall of Fame coach Kay Yow, guided the program to an unexpected run to the ACC championship game in 2010, but her first squad fell to the Blue Devils after four games in four days. This win might be even more memorable than Harper's entire first trip to Greensboro, now that N.C. State figured out a way to beat the two-time defending champion Blue Devils for the first time since the 2007 semifinals.

N.C. State entered the tournament with an 0-11 record this year when trailing at halftime, but the Wolfpack rallied from a 42-35 halftime deficit to Florida State in Thursday's first round to win 74-71. On Friday, the Wolfpack trailed 37-36 at the break but never let the Blue Devils put together any type of clinching run.

Goodwin-Coleman hit the go-ahead 3-pointer to make it 64-62 with 6:12 left, and the Wolfpack pushed that lead all the way to 73-65 on a pair of free throws from Kastanek with 2:54 left.

Tricia Liston hit a pair of 3-pointers to cut into the deficit. And when Emili Tasler missed two free throws with 15.9 seconds left, Duke had the ball with a chance to tie it. Gray drove into the paint and drew the foul on Goodwin-Coleman, but her free throw struck the front iron and the ball went out of bounds.

The Blue Devils had reached the tournament semifinals every year since 1995 and appeared to be in the running for a No. 1 seed in the NCAA tournament. But they struggled all day against a team they beat by 24 points in January and lost their first ACC tournament game since the 2009 final against Maryland.